Tooth-crown.



& 5'

No. 876,043. P-ATENTED JAN. 7, 1908. A. DAVIS. TOOTH CROWN.

APPLICATION FILED APR. 80. 1907.

' WITNESSES A TTO/GNE V5 UNITED STATES PATENT OFFICE.

THOMAS A. DAVIS, OF WARSAW, ILLINOIS.

TOOTH-CROWN.

Specification of Letters Patent.-

Patented Jan. 7, 1908.

Application filed April 30, 1907. Serial l-lo. 371.102.

T 0 all whom it may concern:

Be it known that I, THOMAS A. DAVIS, a

citizen of theUnited States, residing at Warsaw, 1n the county ol Hancock and State of novel means for more securely holding the i crowns in place, and to provide for more aecurate 'httmg than 1n ordinary methods.

With this and other objects in view, as l will more fully hereinafter appear, the invention consists in certain novel features of construction and arrangement of parts, herein after fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages oi the invention.

In the accompanying drawings :Figure 1 is a perspective view, partly in section, illustrating a tooth crown made in accordance with the invention. Fig. 2 is a sectional View of the root showing the manner in which the root is drilled and dressed for the reception of the post. Fig. 3 is a detail perspec tive View of the crown post detached. Fig. 4 is a view corresponding to Fig. 2 showing the crown post introduced into the socket or recess of the root. Fig. 5 shows the-manner in which the crown post is filled with amalgain and expanded into the recess. Fig. 6 is a sectional view showing the first fitting of the crown collar to the post. Fig. 7 is a detail perspective view of the crown collar detached. Fig. 8 is a sectional View showing the first step in preparing the crown plate for attachment to its collar. view showing the manner in which an impression of the collar is taken on the crown plate. Fig. 10 is a plan View of the crown plate with its initial depression. Fig. 11 is a sectional View showing the crown plate with the central portion turned or burnished down. Fig. 12 is a sectional view corresponding to Fig. 9, showing the manner in wh1ch the crown plate is placed on the crown collar and fitted to the root. Fig. 13 is a detail perspective view of the finished crown plate detached from the collar. F let is a detail sectional View showing the crown and Fig. 9 is a similar.

a l l l l l cess, as indicated at 0.

root assembled. Fig. 15 is a similar view showing a gold or metal crown.

Similar numerals of reference are employed to indicate correspomling parts throughout the several -figures of the drawings.

In carryingout the invention the root (1 is 1 drilled out by means of a suitablev bur in order to form a socket or recess 1), and in this first step a squared ended bur maybe employed, after which an inverted cone bur is used in order to undercut the wall of the rel nto this recess is placed a tube 10 formed of copper or other soft metal, the contour of the tube in cross section corresponding to the contour of the upper edge of. the recess. The tube is then tilled with amalgam d, as indicated in Fig. 5, and sullicicnt pressure is exerted on the amalgam to expand the lower edge of the tube into the undercut wall of the recess, so

, that the tube is firmly confined in place, and

together with this 'lilling of amalgam forms a post for the reception of the crown. The post having thus been prepared, a collar 11 is fitted thereto as indicated in Fig. 6, the collar being of the same contour as the post, and of a height equal to the distance between the surface of the root and the upper edge of the post. A thin plate 12' of gold or other suitable metal is then placed over the post and collar, as shown in Fig. 8, and is pressed down by the thumb or linger in order to form a depression, the outer wall of the depression following, of course, the contour of the periphery of the collar 11. This crown plate 12 is then placed on the work bench and is cut by means of a small chisel from the center outward toward the opposite wall of the depression, a number of cuts being made, as indicated at c, Fig. 10. The central portion of the plate is then turned or burnished down in an opening in a suitable block to in order that the points may be bent, as shown in Fig. 11., and the crown plate is then forced over the collar, so that the points will project upward, as shown, for instance, in Fig. 12, and in this case there are four of such points, the collar being approximately rectangular in form.

After the plate has been slipped over the collar, it is burnished down against the end of the root, and the points made by the cuts are burnished against the side of the collar until they closely lit. The plate and collar are then removed and soldered together, so that the lower end of the collar will be in alinement with the lower face of the crown plate. The plate and collar now securely fastened together, are then returned to the post, and an automatic plugger is used to force the plate down against the upper surface of the root, until an imprint of the sur- A suitable porcelain shell or capis then suitably ground to fit and cemented to the collar and plate which may be termed the cap, after which the finished crown is removed from the articulator, dressed down and polished, and is then ready to be placed on the post, any suitable cement being introduced for the purpose of securing the crown in place.

In the manufacture of the crown proper, any of the usual operations may be followed to manufacture a crown of porcelain, platinum, or other material. There a gold shell crown is to be made, as shown in Fig. 15, the method of procedure is similar to that followed up to Figs. 11 and 12. To the crown plate is then soldered a gum band f that is placed a slight distance within the inner edge of the plate. The gold crown is then prepared and telescoped over the band f, as shown in Fig. 15, and united thereto by solder, after which the gold crown may be cemented to the post. The posts and pins for the front and side teeth are to be swaged in one piece with the band and gold rim to telescope over the post, the same as in the molars.

I claim- 1. A tooth crown connection comprising a post secured to the root, a collar encircling the post, a plate secured to the collar, and conforming to the contour of the upper face of the root, and a crown having a recess for the reception of the collar and permanently secured to said plate and collar.

2. A tooth crown connectlon comprlsing a.

post secured to the root and projecting therefrom, a cap including a collar and plate, the collar being arranged to fit around the post, and the plate being shaped to conform to the contour of the upper face of the root, the edge of the plate being turned I down or flanged to follow the contour of the outer surface of the root, and a crown having a recess for the reception of the collar and permanently secured to the collar and plate. In testimony that I claim the foregoing as my own, I have hereto affixed my signature in the presence of two witnesses.

THOMAS A. DAVIS. Witnesses:

M. L. HILL, J. B. DODGE. 

